1. Field
The invention is in the field of eyeglass retainers and particularly of the fasteners at the ends of the retainer cord for attaching the retainer to the ends of eyeglass temple pieces.
2. State of the Art
An eyeglass retainer generally comprises a length of cord or other material of some type with fasteners on the ends to attach the temple pieces of a pair of glasses to respective ends of the cord thereby attaching the glasses to the cord. The retainer then serves to hold the glasses around the user""s neck if they fall off the user""s head during vigorous activity, and allow the glasses to hang around the user""s neck during periods of nonuse to be handy for immediate use when needed.
There are numerous types of eyeglass retainers in use today which include a cord with fasteners at the ends of the cord to attach to the ends of the temple pieces of the glasses to be retained. These traditionally have included as the fasteners a loop of material (often the cord material merely looped at the ends) through which the ends of the temple pieces are threaded so that the temple pieces pass through the loops and are held in the loops. A variation of the loops where the loops are formed of a plastic material attached to the ends of the cord are shown in U.S. Pat. Nos. 5,655,264 and 5,904,938.
Elastic tubes attached to the ends of the cord which stretch as the end of a temple piece is pushed into the tube and then holds the temple piece in the tube by friction, are well known as fasteners and are shown in U.S. Pat. Nos. 2,704,961, 5,575,042, and 6,182,334. While the elastic tubular bodies will stretch over a range of sizes of temple pieces, the wide range of sizes of temple pieces in use on eyeglasses today present a problem. Any elastic material has limits within which it will stretch and the materials and configurations in use today will not accept the wide variations which exist. Thus, while such end fasteners are sized to receive, stretch over, and hold the more common intermediate size temple piece ends, they cannot hold the wide variety of sizes of temple piece ends in use today.
According to the invention, an end fastener for an eyeglass retainer includes an elastomeric body with a temple piece insertion opening and an internal bore extending from the opening into the body. The internal bore varies in diameter from a largest diameter near the opening to a smallest diameter inward of the opening. At least one additional intermediate diameter portion is included. The largest diameter portion of the bore receives and holds large temple piece ends while the smallest diameter portion of the bore receives and holds small temple piece ends, which pass through the larger diameter portions of the bore without being held. Intermediate size temple piece ends are held by the intermediate portion. In this way, the retainer end piece can hold a very wide range of sizes of temple piece ends.
The internal bore preferably includes a bulbous portion adjacent the insertion opening which includes the largest diameter and accepts and holds the larger temple piece ends. An elongate extension, including at least two different diameter portions, extends from the bulbous section to accept and hold smaller temple piece ends. The elongate extension may include tubular portions, may be tapered, or may include various curved portions of varying configuration.